Residential buildings: a comparative analysis of the LEED and ITACA environmental sustainability schemes It d ti It d ti F. Asdrubali, G. Baldinelli , F. Bianchi, S. Sambuco University of Perugia − Department of Engineering − Via Duranti, 67 − 06125 − Perugia − Italy − Email: giorgio.baldinelli@unipg.it Introduction Introduction Energy costs and growing environmental concerns are the catalysts for the high demand for sustainable building facilities with minimal environmental impact. Currently, a number of different rating systems are used to rate the environmental performance of buildings that give different levels of influence to the singular aspect of the environment, respect to the total score. In this work two rating systems were analyzed: LEED (U.S. Green Building Council) and the Italian ITACA Protocol for the assessment of buildings energy and environmental sustainability. The LEED credits take into account environmental principles with a balance between known effective practices Site Quality Resource Consumption Environmental Loads Indoor Environmental Quality Service Quality ITACA ITACA D C B A A+ A+ 100 85 70 55 40 110 80 60 50 40 PLATINUM PLATINUM GOLD GOLD SILVER SILVER CERTIFIED CERTIFIED Sustainable Sites Water Efficiency Energy and Atmosphere Materials and Resources Indoor Environmental Quality Innovation in Design (BONUS) LEED LEED and emerging concepts following six major categories: sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environmental quality, and innovation in design. ITACA certification is composed of 22 technical sheets, dealing with various environmental and energy aspects of the building to be certified, divided into 5 macro−areas: quality of the site, resources consumption, environmental loads, indoor comfort, and quality of the service. For each sheet a score is assigned from ˆpoor˜ (−1) to excellent (+5); the (weighted) sum of the scores obtained in the five evaluation areas generates the final score of the building. The two methods have been compared in order to underline the main 20 30 40 50 LEED ITACA The The histogram histogram shows shows the the performance performance sensitivity sensitivity for for LEED LEED and and ITACA ITACA procedure procedure; it it is is based based on on the the values values in in the the table table. The The items items site site, water water, materials materials, energy energy, indoor indoor environment environment quality quality represent represent new new areas areas common common to to both both procedures procedures. In In this this way way it it is is possible possible to to compare compare the the two two evaluation evaluation systems systems. LEED LEED pays pays more more attention attention to to the the site site The two methods have been compared in order to underline the main differences in the composition of the total score. Six macro−areas have been detected to make the two methods comparable: site, water, materials, energy and indoor environmental quality. Moreover, two green buildings located in Umbria Region (Italy) were certified with LEED and ITACA procedure to determine, for each evaluation systems, which is the final class. site water materials energy indoor environment quality LEED 27/110 LEED 14/110 LEED 23/110 LEED 33/110 LEED 21/110 sustainable site 23 sustainable site 2 materials and resources 15 energy and atmosphere 30 indoor environment quality 20 0 10 site water materials energy indoor env. quality choice, choice, giving giving less less importance importance to to the the energy energy issues, issues, if if compared compared to to the the ITACA ITACA procedure procedure. The The reason reason is is probably probably due due to to the the fact fact that that in in Italy Italy is is much much more more difficult difficult to to choose choose a suitable suitable site site that that fulfills fulfills the the requirements requirements of of sustainability sustainability. LEED SUSTAINABLE SITES 25 16 20 Case studies I sustainable site 23 sustainable site 2 materials and resources 15 energy and atmosphere 30 indoor environment quality 20 innovation in design 4 water efficieny 10 innovation in design 5 innovation in design 3 innovation in design 1 innovation in design 2 ITACA 4/100 ITACA 17/100 ITACA 10/100 ITACA 44/100 ITACA 25/100 site quality 4 resource consumption 6 resource consumption 10 resource consumption 38 indoor environment quality 18 environmental loads 11 environmental loads 6 service quality 7 I II The The building, building, with with parallelepiped parallelepiped form form oriented oriented along along the the east east−west west axis, axis, is is divided divided into into four four levels levels hosting hosting 12 12 simplex simplex or or duplex duplex and and 12 12 underground underground garage garage The The south south ITACA SITE QUALITY 4 1 2 WATER EFFICIENCY 10 7 7 ENERGY AND ATMOSPHERE 30 15 23 MATERIALS AND RESOURCES 15 3 5 INDOOR ENVIRONMENTAL QUALITY 20 3 4 INNOVATION IN DESIGN 10 2 1 110 45 45 60 60 II into into four four levels levels hosting hosting 12 12 simplex simplex or or duplex duplex and and 12 12 underground underground garage garage. The The south south façade façade is is characterized characterized by by the the presence presence of of large large windows windows shielded shielded by by fixed fixed solar solar shading shading and and blinds blinds during during the the summer summer. The The roof roof is is characterized characterized by by the the presence presence of of a "roof "roof garden" garden" and and pitched pitched roofs roofs that that allow allow the the placement placement of of solar solar panels panels and and photovoltaic photovoltaic systems systems. The The radiant radiant heating heating is is centralized, centralized, with with separate separate accounting accounting systems, systems, and and powered powered by by geothermal geothermal energy energy and and heat heat pumps pumps. The The building building is is insulated insulated by by panels panels of of wood wood fiber fiber and and expanded expanded polystyrene polystyrene. The The residential residential complex complex ˆMolino ˆMolino albergo albergo la la nona nona" consists consists of of three three parallelepiped parallelepiped shaped shaped buildings buildings oriented oriented along along the the east east−west west axis axis. Each Each building building has has 7 apartments apartments CERTIF. GOLD 100 LEED SITE QUALITY 4 1 2 RESOURCE CONSUMPTION 54 32 33 ENVIRONMENTAL LOADS 18 14 18 INDOOR ENVIRONMENTAL QUALITY 18 6 5 SERVICE QUALITY 6 1 4 100 54 54 62 62 I 100 LEED II distributed distributed in in 3 levels levels. The The internal internal distribution distribution follows follows the the same same structure structure: living living room room with with south south−facing facing solar solar greenhouse greenhouse and and north north−facing facing service service rooms rooms. All All buildings buildings are are characterized characterized by by a pitched pitched roof roof that that allows allows the the placement placement of of solar solar panels, panels, and and they they are are fully fully insulated insulated: the the roof roof by by wooden wooden panels panels and and the the perimeter perimeter walls walls by by glass glass wool wool. Particular Particular attention attention is is paid paid to to the the recovery recovery of of water water: in in the the construction construction there there is is a system system of of rainwater rainwater recovery recovery and and a phytopurification phytopurification plant plant for for domestic domestic wastewater wastewater. The The radiant radiant heating heating is is centralized, centralized, with with separate separate accounting accounting systems systems. C B 0 50 site water materials energy indoor env. quality LEED ITACA LEED 14 10 3 15 3 ITACA 1 15 5 25 8 LEED 18 10 5 23 4 ITACA 2 17 7 27 9 I 0 50 site water materials energy indoor env. quality LEED ITACA II The The histograms histograms I and and II II are are associated associated with with the the two two buildings buildings described described above above and and show show the the comparison comparison between between the the items items scores scores of of the the certifications certifications. Each Each result result has has been been standardized standardized to to the the maximum maximum score score of of the the item item. In In the the first first case case it it is is showed showed that that the the scores scores in in LEED LEED are are always always lower lower than than ITACA, ITACA, except except for for the the site, site, and and the the in in the the second second case case is is particular particular that that LEED LEED gives gives more more points points to to energy energy respect respect to to ITACA ITACA. Conclusion Conclusion The methods LEED and ITACA for the environmental sustainability assessment have been compared to underline the main differences in the composition of the total score. LEED gives more attention to the quality of site respect to the energy issues, probably because in Italy there is not a high possibility to choose the construction place. Water is an important subject for both methods of certification, nevertheless, it is easier to get high scores withITACA, as it shifts the attention only to the reuse of water, while LEED analyzes the percentage of water saved in general. The difference that emerges analyzing the materials in the 2 buildings is derived from the difference of interpretation of recycling: LEED analyzes the amount of recycled materials used while ITACA is based on the amount of recyclable materials used. In conclusion, we can notice the two evaluation methods give similar final results, so the tools do not produce significantly different classifications of the environmental buildings performance.